As shown in the photos, I place the ribbon mics around 2 feet back from the speaker cab. Place your hand in front of the amp to feel the air pressure coming from the speaker. Certain ribbon mics are sensitive to air blasts, so to avoid damage to the mic, move it back from the speaker until you can’t feel the air coming from it. You can move the mic in a little closer - 9 inches is as close as I usually go.